Sub- continent was not British country, they were conqueror and made colonies forcefully, but america participated in world wars, on a promise that allies will not make colonies and they have to leave, so uk have to leave, and sub continent was not their country,
As you said uk was failed to defeat these men, but TTP was not defeated? there was increase in causality now a days, because most of soldiers use Toyota and similar truck.
they release more than 100 ttp terrorist, you will see they will join ISIS-K, and if you surrender just bunch of terrorists, who will you fight with India and others?
most of people were claiming of fake news, when international media reported Good Taliban released TTP from jails,if news was fake how can good taliban or their friend become mediate b/w ttp and Pakistan, if they have no links?